The streets of Zimbabwe's capital, Harare, erupted in celebration Tuesday after President Robert Mugabe resigned, ending 37 years in power.

His former vice president, Emmerson Mnangagwa, will be sworn in as president on Wednesday or Thursday, according to top officials in the ruling ZANU-PF party. Mnangagwa, who fled the country after he was abruptly fired on November 6, "is not far from here,'' ruling party official Lovemore Matuke said.

Car horns blared as people danced, cheered and waved to celebrate the news of Mugabe's departure, which he announced in a letter read out by the speaker of parliament.

One man told VOA's Zimbabwe Service: "This is a breakthrough...We are super excited as Zimbabweans and we want to thank God. Our prayers have been answered. We have suffered a lot for 37 years."

Speaker Jacob Mudenda read out the resignation letter soon after lawmakers began proceedings to impeach Mugabe.

The letter said in part, "I, Robert Gabriel Mugabe, in terms of Section 96 of the constitution of Zimbabwe, hereby formally tender my resignation...with immediate effect."

There has been no confirmation of the letter from the president or his office -- but no denial, either.

The 93-year-old Mugabe had ruled Zimbabwe since the country won independence from Britain in 1980.

A protester holds a poster showing support for ousted Zimbabwean Vice President Emmerson Mnangagwa, in Harare, Zimbabwe, Nov. 18, 2017. Mnangagwa is to be sworn in as president Wednesday or Thursday.

History of rights violations

The president was often criticized for human rights abuses that included the beatings, torture and killings of his political opponents. Western countries imposed sanctions on Mugabe and his allies after his supporters began seizing white-owned farmland in 2000. Zimbabwe's farm output and economy plummeted when the land was given to blacks with little experience in large-scale farming.

Criticism intensified in 2008, after inflation reached 231 million percent and Zimbabwe was forced to abandon its dollar. The country experienced new economic problems in recent years, as corruption and Mugabe's heavy-handed economic policies scared away investors.

The U.S. Embassy in Zimbabwe called Tuesday a historic moment for Zimbabwe and said the country must move toward free elections in which Zimbabweans choose their own leaders.

The U.S. State Department echoed the sentiment. "The resignation of Robert Mugabe is a historic opportunity and historic moment for the people of Zimbabwe. The people of Zimbabwe have firmly voiced their desire for a new era to bring an end to Zimbabwe's isolation and allow the country to rejoin the international community," State Department spokeswoman Heather Nauert said.

British Prime Minister Theresa May released a statement that said Mugabe's resignation gives Zimbabwe the opportunity to pursue a path free of oppression.

Rights group Amnesty International said the next generation of leaders in Zimbabwe must abide by the constitution and treat the population with respect.

Mugabe had faced growing pressure to resign since last week, when the military took over state institutions and put him and his wife Grace under house arrest.

The military took action after the president fired the vice president, Mnangagwa, a hero of Zimbabwe's liberation war, and hinted he would replace Mnangagwa with Grace Mugabe. The first lady and former vice president were locked in a political battle over who would succeed the aging president, and led competing factions in the ruling party.

Until Tuesday, Mugabe showed no sign of stepping aside. He even called a Cabinet meeting for Tuesday morning. According to the Reuters news agency, only a handful of the 17 ministers showed up.

Mugabe was planning to run for another term as president in next year's elections, when he would have been 94.